Safety brake device



May 31, 1932. 1 C, MCCUNE SAFETY BRAKE DEVICE Filed Jan. 2l, 1930 n m R U o c n c .A .MW RG www NE Es v Y No lnvB J Patented May 31, 1932 UNITED STATES PATENT .o1-*FICE .JOSEPH PENNSYLVANIA C. HCGUNE, F EDGEWOOD, PENNSYLVANIA, ASSIGNOB TO THE WESTHQ'GHOUSE 1" COMPANY, OIF WILHEBDING, PMBYLVANIA, A CORPORATION 0E sarnrr nam nnvrcn application ma January 21, 19m. semi m. 422,303.

This invention relates to brake controllingv equipment of the type in which brakes are automatically applied when the operator of v the vehicle vbecomes incapacitated and 5 adapted more particularly for use on passeilclar buses of the tracklesstype. Y

e object of my invention is to provide an equipment of the above character having improved means for automatically applying the brakes when the operator becomes incapacitated. l

Another object of m invention vis to provide a vehicle controlllng means wherein a safety control valve and a service brake pedal are adapted to be operated by one foot of the operatorof the vehicle.

In the accompanging drawing, a diagram-l matic view of a sa ety brake equipment and a controlling'mechanism therefor, as constructed in accordance with my invention,

is shown.k

As shown in the drawing, the apparatus com rises a service brake operating pedal 1, a sa ety control valve device 2, a main reservoir 3, a brakev device 4, a brake cylinder 5,

and interlock switch device 6. The safety control valve device comprises a casing havin@r a hollow cap 9, a valve stem 1 0' extending through a bore in the cap and luted intermediate its ends. A double beat valve 11 is formed on the valve stem intermediate its ends and. adapted to seat in one direction on, valve seat' 12 when the vehicle operator applies foot pressure to a head 13 on the valve stem 10. A collar 14 is formed 'integral with the double beat `valve 11, and' a coil spring 15, seated in a recess 16 of the safety control valve device 2 engages the underside ofthe collar 14 andetends to move the stem 10 outwardly ofthe casing 8 of the safety control when pressure or weight is removed from the head'of the valve stem:` The main reservoirv 3 is connected to the safety valve casing by a pipe 17.

The brake valve device 4 comprises a casing formed intwo parts between which a flexible diaphragm 18 is secured, Iforming av prewure chamber inthe lower art ofthe casing. The ca or upper part o the casin 59 is provided wit an opening through whi a pin 19 extends. A shoulder 20 is formed on the lower end of the pin 19 to limit the outward movement of. same and also to act as a bearing base for one end of a coil spring 21. The lower 'end .of said coil spring seats -on al plate 22 through which the pressure of is transmitted to diaphragm 18.

ivotall mounted at 23 on the casing 4 is an L-shape arm l24,' which is adapted to engage the pin 19 so as to compress spring 21. One end of the arm 24 is provided with a rece'ss 25 in which is mounted a coil spring 26, the lower end of said coil spring bearing against the top of the casing 4 and tending to hold the recess end bf the arm out of engagement with the pin 19.

An inlet valve 28'is mounted inthe casing 4 and controls 'iiuid under pressure from pipe 17 leadin from the main reservoir 3, to pressure chamer 50. 'A rocking bar 35 which is operatively connected to the diaphragm 18, engages the stem of valve 28, and a spring 29 urges the valve to its seat.

A release valve 30 is also mounted in the casing and has a stem adapted to en a e the 'l5 bar 35. A coil sprin 31 tends to go d the valve 30 unseated. ad of the release valve 30 controllin direct communication from chamber to t e atmosphere, the valve controls communication from said chamber to a pipe 32, which is connected to a pipe 33, leading to vulve chamber 51 of the safety control valve device 2.

The interlocking switch device 6 comprises a cylinder containing a piston 42. One end of the cylinder of said interlocking switch is closed by a screw plug 36. Mounted on inpring 21 .sulating blocks 37 and secured to the plug 36 are contact switch points 38. A contact member 39 mounted on the free end of the stem of piston 60 is adapted to connect and close a clrcuit 40 through the contact members 38. A coil spring 41 acts on piston 42 and tends to maintain the piston in a position infwhich the contact member 39 engages the contacts 38.

The 'circuit rom the motor 8, which is the driving motor of the vehicle, to the trolley wire 52 is controlled by a switch member 45 and the operan'on of the switch member is 100 controlled by a magnet coil 53. The current for energizing the coil 53 is supplied from the trolley Wire -52 through a resistance and a wire 40 connected to one of the switch contacts 38. The other switch contact 38 is connected to a wire 54, leading to the coil 53.

The L-shaped arm 24 and the foot service brake pedal 1 are connected by a pivoted crank 57 and a connectin rod 58. It is to be understood that the service brake pedal and the safety control valve are operated by the same foot of the operator of the vehicle, and that ressure must be maintained on the head 13 o the valve 10 by the heel of the operator while using the ball of the foot for making a service application of the brakes.

In operation, with no pressure applied to the service brake pedal 1, the spring 21 in the brake valve device is not under pressure and the diaphragm 18 does not exert pressure on the valve stem of the inlet and release valves 28 and 30. The inlet valve 28 is then held seated by spring 29, while the release valve 30 is held unseated by sprin 31. If the push button 13 is held depresse by the foot of the operator, the double beat valve 11 will be held seated on the seat 12, while it will be unseated at the seat 55. With the double beat valve in this position, the pipe 33 is open to the atmosphere by the way of chamber 56 and atmospheric exhaust port 43.

The pressure chamber 50 of the brake valve device and consequently brake c linder 5, which is connected to said chamber through pipe 34, is therefore vented to the atmosphere.

Assuming that the vehicle is travelling with the braking apparatus in position -as stated above and itis desired to make a service a plication of the brakes, pressure is applie to the foot operating pedal while still maintaining a pressure on the valve stein 10, which causes the L-shaped arm 24 to swing on its pivot 23, thus moving the free end of said arm downwardly-into engagement with the pin 19 and continuing the pressure until the pin 19 is moved so as to compress the spring 2l against the ldiaphragm 18. The diaphragm is then moved by spring pressure so as to depress the bar 35. The movement of bar 35 first acts to seat the valve 30 and then to unseat the valve 28, thereby permitting the fluid under pressure from main reservoir 3 to flow to chamber 50, then by means of pipe 34 to pass on into the brake cylinder 5. This movement will in no way affect the interlocking switch 6, as the closed valve 30 will prevent luid under pressure from entering same. When the pressure of fluid in chamber 5() and the brake cylinder has been increased suiciently to overcome the pressure of spring on the diaphragm 18, the diaphragm will be moved upwardly so as to permit the valve 28 to seat and cut of the further supply of 'fluid under pressure to the brake cylinder, thereby maintaining the brakes in what is known as a lap position.

Should the operator of the vehicle become incapacitated and remove the weight of his foot from the head of the valve stem 10, the said valve stem would be moved in an upwardly direction by the tension of the coil spring 15, so that the double beat valve 1l will seat at 55 and will unseat at the valve seat 12. Fluid under pressure will then be supplied from the main reservoir 3 to pipe 33, and if the brake device is in release position, fluid under pressure will be supplied from pipe 32 past the unseated valve '30 to chamber 50 and through pipe 34 into the brake cylinder 5, thus making an emergency application of the brakes. At the same time the fluid under pressure is entering the brakey cylinder, the same is also passing into the cylinder of the interlocking switch 6 to force the piston 42 outwardly against the tension of the spring` 41, thereby breaking the circuit 40 at contact points 38 which deenergizes the magnet 53.to allow the switch 45 to open, thus stoppingthe motor 8. l

From the foregoing description, it can be readily seen that in order to release the brakes, the valve stem 10 must be moved to the position shown in the drawing, thus the fluid under pressure is permitted to iiow from the brake cylinder and the interlocking switch cylinder through pipes 34, 32 and 33 to the safety control valve device and then exhausted to the atmosphere by the way of the chamber 56 and exhaust port 43.

While one illustrative embodiment of the invention has been described in detail, it is not my intention to limit its scope to that embodiment or otherwise than by the terms of the appended claims.

Having now described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. In a fluid pressure brake equi ment, the combination with a brake cylinder and a. brake valve device for controlling the admission to and the release of fluid under pressure from the brake cylinder, of a safety control valve device movable by the o erator to es tablish communication throng which fluid is released from the brake cylinder by operation of said brake valve device and operative upon release by the o erator to supply fluid under pressure to the brake cylinder.

2. In a fluid pressure brake equi ment, the combination with a brake cylin er and a brake valve device for controlling the admission to and the release of fluid under pressure from the brake cylinder, a foot pedal for operating the brake valve device to permit admission of fluid under pressure to the brake cylinder, and a safety control valve movable by the operatorto establish communication through which fluid is released from the brake cylinder and operative upon release by the o rator to snpply iuid under pressure to t e brake cylm er'.

3. In a fluid pressure brake equlpment, the combination with a brake cylinder and abrake valve device for controlling the admission to and the release of iluidunder pressure -fr om the brake cylinder, a foot pedal for operating the brake valve device, a safety control valve device adjacent the lfoot pedal and movable m by the o erator for supplylng to and exhaustin fiui under pressure from the brake cyl- 1n er.

4. In a vehicle controlling mechanism, the combination with a fluid pressure brake including a brake cylinder and a brake valve device for controlling the admission and release of fluid under pressure to and from the brake cylinder, of a motor for the vehicle, a. circuit through which the operation of the motor is controlled, electrically operated switch means for controlling the openin and closing of said circuit, and manuallgy operable valve means for controlling communication through which fluid is released from the brake cylinder by operation of said brake valve device and operatlve upon the relief of manual pressure for eiecting an application of the brakes and the operation of said electrically operated switch means to open said circuit.

5. In a vehicle controlling mechanism, the. combination with a fluid preure brake including a brake cylinder and abrake valve device for controlling the admission and re- 'lease of iluid under pressure to and from the brake cylinder, of a motor for driving the vehicle, a circuit through which the operation of the motor is controlled, a switch for con trolling the opening and closing of said circuit, a liuid 'pressure operated plston for controlling operaton ofsaid switch, and manually operable valve means for contro communication through which fluid is released from the brake cylinder by operation of said brake valve device and operatlve lfllpon relief of manual pressure for supplying uid under pressure to the brake cylinder and to said piston to operate said switch to open said circuit.

In testimony whereof I have hereunto set my hand, this 17th day of January, 1930.

JOSEPH C. MOCUNE. 

